| 三门海游构造火山盆地之火山─沉积岩系层位归属讨论 |
| |
| 引用本文： | 翁祖山.三门海游构造火山盆地之火山─沉积岩系层位归属讨论[J].浙江国土资源,1997(1). |
| |
| 作者姓名： | 翁祖山 |
| |
| 作者单位： | 浙江省第五地质大队!宁波，315010 |
| |
| 摘 要： | 本文根据天台测区1：5万区域地质调查工作成果，综合测区构造，岩石组合，岩石化学、化石，接触关系特征等资料分析，对三门海游构造火山盆内龙珠山─下路朱一带及芹溪、三门中学等地出露约70km2的火山─沉积岩系地层，进行层位归属讨论。指出海游盆地内龙珠山、里金、下路朱一带及芹溪、三门中学等地出露的火山─沉积岩地层，其层位应归属下白垩统永康群馆头组和朝川组，系属北北东向展布的早白垩世临海断陷地的组成部分。
|
| 关 键 词： | 火山─沉积岩系 层位归属 下白垩统 海游盆地 |
DISCUSSIONS ON THE STRATIGRAPHIC HORIZON OF THE VOLCANO-SEDIMENTARY ROCK SERIES IN HAIYOU STRUCTURAL VOLCANIC BASIN, SANMEN COUNTY |
| |
| Authors: | Weng Zushan |
| |
| Abstract: | There is a volcano-sedimentary stratum developed in Longzhushan Area, Haiyou Basin of Sanmen county, with an area of about 7Okm2. The disputes on the age of this horizon have been lasted for a long time. Our recent regional surveying (l: 5O, OOO) defined the stratigraphic sequence again, collected some standard fossi1s of early Cretaceous period, and considered that it corresponded to Guantou Formation and chaochuan Formation of lower Cretaceous series. This is based on:1. Features of stratigraphic distribution. The formation and development of this basin wascontrolled by the NNE Wenzhou-Zhenghai Fault. The basin occurred in large-scaled Xi struc-ture and NNE 25"~3O extension. The ocurrence of its strata dipped to the basin center, withthe dip angle of 2O~3o". The strata within the basin were discordant with the undrlying Moshis-han Group.2. Features of rock assemblage. The total thickness of the stratum was more than 239m.The' lower member of Guantou Formation was composed of variegated fluviolacustrine sedimenta-ry rocks, with conglomerate developed at the bottom j the upper member of Guantou Formationwas interbedded by sedimentary rocks and volcanic rocks, with basaltic andesite and marl ofabove 2o metersl thick developed; the lower member of Chaochuan Formation was composed ofvolcano-sedimentary rocks; and the upper member of Chaochuan Formation was rhyolite porphyry.3. Features of 1ithochemistry. The volcanic product with 53%-66% SiO, was lacked. Thevolcanic rocks had the typical features of bimodal type.4. Features of fossils. The Ostracoda combination was CyPrdea- Dr~ula- LycoPtero-cypris. Besides, we found typical eccentric oncolite and LLH-type stromatolite this time-To sum up the above-mentioned features, it is clear that the strata in Haiyou StructuralVolcanic Basin of Sanmen county belonged to ear1y Cretaceous system, and its horizon corre-sponded to Guantou Formation and Chaochuan Formation of Yongkang Group. |
| |
| Keywords: | Volcano-sedimentary rock series Stratigraphic horizor Lower Cretaceous series Haiyou basin |
| 本文献已被 CNKI 等数据库收录！ |
|
